Recently, the Federal Communications Commission (FCC) proposed new rules that would allow unlicensed cognitive radios to operate in geographically unused television (TV) channels. While the new rules may introduce numerous channels for use by the cognitive radios, several licensed transmissions occupy the TV channels including analog TV, digital TV, and professional wireless microphones. If any of these licensed transmissions is present above a certain power threshold, then the TV channel is deemed to be occupied; otherwise, the TV channel is deemed to be unoccupied and hence available for unlicensed wireless use. Thus, there is a need for methods and apparatus for determining if a signal of interest, for example, a licensed signal, such as a television broadcast signal having or exceeding a predetermined field strength, is present in a wireless spectrum and/or which facilitates such a determination.